ChipMOS ( IMOS) slid after hours Tuesday on 2005 revenue guidance that trailed analyst estimates.

The semiconductor test equipment maker, whose full corporate name is ChipMOS Technologies (Bermuda) Ltd., sees 2005 revenue of $520 to $550 million. The Thomson First Call consensus of three analysts is for revenue of $583.4 million.

Full-year margins should be in line with previous estimates of 25% to 30%, ChipMOS said.

The company also posted December 2004 revenue of $41.4 million, up 39.7% from last year's $29.6 million.

The stock fell 45 cents, or 7.6%, to $5.50 after the bell Tuesday.